1. Field
The present disclosure relates generally to manufacturing and, in particular, to manufacturing objects. Still more particularly, the present disclosure relates to a method and apparatus for inspecting operations performed on an object.
2. Background
In manufacturing objects, machining of an object may be performed to remove materials from the object. Machining may be performed using power-driven machine tools such as lathes, milling machines, drill presses, and other suitable tools. Machining may include processes such as, for example, without limitation, turning, drilling, milling, and other suitable processes.
Machining may require attention to many details for an object to meet specifications set out in engineering drawings or computer-aided design models. These details may include, for example, without limitation, correct dimensions, correct finish, and other suitable parameters.
Computer numerically control (CNC) tools may be used to perform various machining operations. A computer numerically controlled tool may perform machining operations in response to instructions in a program. This type of program may also be referred to as a parametric program. A parametric program may be created from a computer-aided design model of the object. The machining process may include, for example, without limitation, roughing, semi-finishing, finishing, contour milling, and other suitable processes. These, and other similar processes, may generate machined features on an object.
Although computer numerically controlled machines may provide a high degree of accuracy, verification of the machined features may still be performed to ensure that the machined features are within tolerances defined for the particular object. Certain conditions may result in the machined features being out of tolerance. For example, without limitation, unusual wear of a drill bit, faulty encoders, or other conditions may result in machined features for an object being out of a tolerance.
For example, a groove machined into an object may be deeper than specified for the object. The groove also may be in a location that is offset from the location in the design. As another example, a beveled edge created from machining may be wider than specified for the object. If the differences are greater than some threshold, these features may be considered out of tolerance.
Currently, the verification may be performed in a number of different ways. For example, a coordinate measuring machine may be used to measure the physical geometric characteristics of the object. This machine may be manually controlled by an operator or may be computer controlled. Measurements may be made by a probe attached to a moving axis on the coordinate measuring machine. The probe may touch the part of interest and may allow for collecting discreet points of data on the surface of the object.
The use of these machines to verify whether the machined features fall within a tolerance may occur after the object has been processed. This type of verification of machined features may require more time because of the additional time needed to measure and analyze the machined features. The amount of time required may vary depending on the number of measurements taken. For example, an object may be machined in about one hour. Two or more hours, however, may be needed to inspect the object.
This type of inspection may increase the time and expense for creating objects. Further, the output of objects in a manufacturing facility may be slowed down because of the time needed to inspect objects.
One solution may be to only perform an inspection of portions of the machine features. This type of sampling may reduce the amount of time needed to inspect the machine features of an object. This process, however, may result in unexpected portions of the features that are out of tolerance being undetected.
Thus, it would be advantageous to have a method and apparatus that overcomes one or more of the issues discussed above.